If we'd only stayed for the mojitos I might have liked the Chicago Rib Shack. They were good ones, properly crushed and beaten and muddled, much like me on a Saturday night. Unfortunately we stayed for dinner, too, so now I hate the place. I hate the clumsiness, the lack of quality control, the sheer bloody mediocrity of the whole operation. What I do not hate are spare ribs. I like spare ribs. No, I love spare ribs. I love eating with my hands, ripping shards of meat from bones, lapping away at the knobbly bits at the end, smearing the sauce in all the right places.

Happily, London has Bodean's, where I can get serious barbecue action. This, of course, is southern US barbecue, which is not the blackened raw-sausage experience of a million British summer garden parties. It is about long and slow and deep. British barbecuing is a sprint; American is a marathon. As a friend of mine who has eaten across the barbecue belt of the southern US put it, Bodean's is on a par with the barbecue pits of Dallas. Which is not at all bad for somewhere so far off the territory. The ribs have the right balance of meat to fat, the marinades are varied, and there are two nice sauces to apply at the counters.

I tell you all this by way of comparison. Because by comparison, the Chicago Rib Shack stinks, in the way old fish that's been left on the parcel shelf of a locked car for three weeks throughout an Arizona August stinks. It's a waste of ribs, an insult to pigs and cattle. It's a sauce crime, and it's taking place right in the heart of Knightsbridge. Call the food police. Now! According to its own publicity, the Chicago Rib Shack isn't a restaurant, it's a national institution. Then again, so was Bernard Manning, and I wouldn't have gone round his house for dinner, either.

The original Chicago Rib Shack was set up by the much-loved American Bob Payton a couple of decades back. Then he was killed in a car crash and it closed. Now, apparently, it's back due to 'popular demand'. Whose popular demand?

The new rib shack occupies a two-floor barn of a site that has been a coffin for two other restaurant ventures - Isola and Mocoto - in recent years. This one seems to be doing a brisk trade, but don't let popularity be a guide to quality. You should see the audience figures for The Jeremy Kyle Show Certainly it looks the part: all dark wood, brass rails and pig memorabilia. The problem is the food. Or, more particularly, the ribs. First, the cuts are meagre. I would love to know what they do with the rest of the meat they cut off the beef short ribs. Short ribs are huge. These are skinny, denuded, heavy with naked bone. Likewise, baby backs are thin and insubstantial and far too lean. But the real problem is the sauce, which is completely one note - and that note is sugar. It doesn't just turn up on the ribs, but on the chicken, the pulled pork, the brisket and the pecan pie. OK, I made up the last one, but it might as well be there because the taste lingers until morning. Potato skins at the start came slathered in waxy cheese which hid a centre of hot rather than cooling sour cream. A Caesar salad with stale-tasting croutons (though weirdly good anchovies) was a disgrace to the name. Macaroni cheese was like a bad production of Ibsen: dull and lifeless. The chicken manages to have wet, slippery skin and dry meat, while the pulled pork and the brisket are just damp, rather than smokey and luscious from hours over burning wood. And all of them taste exactly the same: sugar, sugar, and more damned sugar. At the end of dinner here you don't need coffee. You need a syringe full of insulin to stave off type 2 diabetes.

What I find extraordinary is that just one meal at Bodean's would make them realise how bad a job they are doing. It would make them drop their heads into their arms and sob. And it isn't cheap here. With a mojito and two beers each, we ended up with a bill of £110. Ribs are meant to be democratic food, credit-crunch food, not rev-the-Porsche food.

So what was to like? The beer list and the cheery waiters. Oh, and leaving. I liked doing that very much.